High voltage circuit breaker, especially a gas-blast circuit breaker

ABSTRACT

In a high-voltage power breaker having two mutually opposite switching contacts which, when connected are surrounded by an insulating material nozzle, coaxially with respect to which a shielding electrode is arranged, with a first switching contact, which can be driven, being connected via the insulating material nozzle and a linkage to the second switching contact, such that said switching contact carries out a movement in the opposite direction to the first switching contact during operation of the latter, the shielding electrode is operatively connected to the second switching contact such that, during disconnection, it carries out a movement which controls the electric field in the switching gap.

CLAIM FOR PRIORITY

This application claims priority to International Application No.PCT/DE00/00175 which was published in the German language on Jul. 20,2000.

The invention relates to a high-voltage power breaker, and inparticular, to a gas-blast power breaker.

BACKGROUND OF THE INVENTION

A high-voltage power breaker is disclosed, for example, in DE 196 22 460C2. In this high-voltage power breaker, the two mutually oppositeswitching contacts are surrounded by an insulating material nozzle whenconnected. The insulating material nozzle is connected to the firstswitching contact, which can be driven. The second switching contact iscoupled by a linkage and a direction-changing lever to the insulatingmaterial nozzle such that, during operation of the first switchingcontact, the second switching contact carries out a movement in theopposite direction to it. In order to improve the field control in theinterior of the high-voltage power breaker, the shielding electrode isarranged coaxially with respect to the insulating material nozzle. Inorder to increase the mutual movement during a switching operation, theshielding electrode is coupled to the direction-changing lever.

A transmission rod, which is rigidly connected to the insulatingmaterial nozzle, is used for coupling the insulating material nozzle tothe direction-changing lever. Another transmission rod is used fordriving the shielding electrode. Depending on the use of thedirection-changing lever, these transmission rods are arrangedeccentrically and on one side, which results in an asymmetric load onthe insulating nozzle and shielding electrode. In addition to thedesired optimum linear force transmission, forces occur which lead totilting and tipping of the shielding electrode. Additional guide devicesare required in order to ensure that the shielding electrode moveslinearly. In order to allow the forces that occur in the process to beabsorbed, the shielding electrode must be designed to be sufficientlymechanically robust. These mechanical requirements result in an increasein the moving masses, which is unnecessary per se from the electricalengineering point of view.

SUMMARY OF THE INVENTION

In one embodiment of the invention, there is a high-voltage powerbreaker, comprising: first and second mutually opposite switchingcontacts when connected, are surrounded by an insulating material nozzlecoaxially with respect to which a shielding electrode is arranged, thesecond switching contact performing a movement in the opposite directionto the first switching contact, which can be driven, during operation ofthe first switching contact, and the shielding electrode controllablebased on coupling by a linkage to the second switching contact, in themovement direction of the first switching contact at a speed whosemagnitude is less than the speed of the first switching contact, whereinthe insulating material nozzle is connected to two tie rods which arediametrically opposite one another with respect to the center axis ofthe switch, and extend parallel to the second switching contact and arefirmly connected on the side facing away from the insulating materialnozzle to a first holder, the first holder is arranged such that it canmove axially and on which two connecting rods are arranged such thatthey can pivot, each of which is connected in an articulated manner toone limb of a fork, the fork is guided such that it can rotate in afixed bearing and has a lever on its side essentially opposite thelimbs, to which lever a coupling lever is connected such that it canpivot and is connected to the contact rod which is fit to the secondswitching contact and can move axially.

In one aspect of the invention, the angle α between the limbs of thefork and the lever is greater than 90.

In another aspect of the invention, another connecting rod mounted in anarticulated manner on each limb of the fork, the connecting rods eachconnected such that they can pivot to a second holder, which is arrangedon the first holder such that it can move axially, and on which two pushrods are arranged in a fixed manner and are connected to the shieldingelectrode.

In still another aspect of the invention, in the central region of thelimbs of the fork, the connecting rods are connected to the fork in anarticulated manner such that, during disconnection, the distancetraveled by the shielding electrode is shorter than that traveled by thesecond switching contact.

In yet another aspect of the invention, the fixed bearing which guidesthe fork such that it can rotate, is arranged on the outer circumferenceof a stationary tube guiding the contact rod, and at a distance fromtube, and the coupling lever, which is connected to the lever of thefork such that it can pivot and is connected to the contact rod, isintroduced into the stationary tube via an elongated hole within saidstationary tube.

In another aspect of the invention, the fixed bearing which guides thefork such that it can rotate, is connected to the stationary tube.

In yet another aspect of the invention, the fixed bearing which guidesthe fork such that it can rotate is arranged on the end face of astationary tube which guides the contact rod.

BRIEF DESCRIPTION OF THE INVENTION

The invention will be illustrated and explained in more detail withreference to an exemplary embodiment in the drawings.

FIG. 1 shows a partial sectional view of a gas-blast power breaker.

FIG. 2 shows a partial view of the gas-blast power breaker shown in FIG.1, with a module arranged differently to the arrangement in FIG. 1.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The invention relates to a high-voltage power breaker, in particular agas-blast power breaker, having two mutually opposite switching contactswhich, when connected are surrounded by an insulating material nozzlecoaxially with respect to which a shielding electrode is arranged, withthe second switching contact carrying out a movement in the oppositedirection to that of the first switching contact, which can be driven,during operation of the latter, and the shielding electrode beingcontrollable on the basis of coupling by means of a linkage to thesecond switching contact, in the movement direction of the firstswitching contact at a speed whose magnitude is less than the speed ofthe first switching contact.

The present invention provides a high-voltage power breaker of the typementioned initially whose moving parts have less mass to be accelerated.

An insulating material nozzle is connected to two tie rods which arediametrically opposite one another with respect to the center axis ofthe switch. They also extend parallel to the second switching contactand are firmly connected on the side facing away from the insulatingmaterial nozzle to a first holder which is arranged such that it canmove axially and on which two connecting rods are arranged such thatthey can pivot. Each is connected in an articulated manner to one limbof a fork which is guided such that it can rotate in a fixed bearing andhas a lever on its side essentially opposite the limbs, to which lever acoupling lever is connected such that it can pivot and is connected tothe contact rod which is fit to the second switching contact and canmove axially.

The angle α between the limbs of the fork and the lever to which thecoupling lever is connected such that it can pivot should expediently begreater than 90°.

Hence, during disconnection, the contact rod which is fit with thesecond switching contact travels through a sufficiently long distanceduring its axial movement to ensure that an isolating gap which can behighly loaded, is formed between the switching contacts as a result ofthe mutual movement of the two switching contacts, which are oppositeone another.

The coupling lever is connected to the contact rod, which is fit withthe second switching contact, via a joint arranged on the contact rod.The joint may in this case be any configuration and which results inaxial movement of the contact rod which is fit with the second switchingcontact, during pivoting of the coupling lever.

In an alternative embodiment of the invention, a movement, whichcontrols the electric field in the switching gap, of the shieldingelectrode, which is arranged coaxially with respect to the insulatingmaterial nozzle but is not connected to the insulating material nozzleis achieved during an opposite movement of the second switching contact.This is carried out during disconnection, by mounting a furtherconnecting rod in an articulated manner on each limb of the fork, whichconnecting rod is in each case connected such that it can pivot to asecond holder. This is arranged on the first holder such as it can moveaxially, and on which two push rods are arranged in a fixed manner andare connected to the shielding electrode.

In this case, in the central region of the limbs of the fork, theconnecting rods are connected to the fork in an articulated manner.During disconnection, the distance traveled by the shielding electrode,whose direction always corresponds to that of the first switchingcontact and the magnitude of whose speed is always in this case lessthan the speed of the first switching contact, is shorter than thattraveled by the second switching contact. The connection of theseconnecting rods to the limbs of the fork, in its central region, at thesame time satisfies preconditions. The preconditions are met such thatthe most suitable articulation point along the limbs of the fork for amovement of the shielding electrode, which provides optimum control ofthe electric field in the switching gap, can be selected for thearticulated connection of these connecting rods to the limbs of thefork. This means that the use of further shields in the region of theswitching gap can at least be reduced.

The invention can also operate independently of the arrangement of thefixed bearing which guides the fork such that it can rotate. Thus,according to one preferred embodiment, this can be arranged on the outercircumference of a stationary tube, which guides the contact rod, and onwhich the first holder is arranged such that it can move axially, and ata distance from it. With this arrangement of a fixed bearing, which canbe connected to the stationary tube, the coupling lever, which isconnected to the lever fork such that it can pivot and is connected tothe contact rod, is advantageously introduced into the stationary tubevia an elongated hole within said stationary tube. However, this doesnot prevent the coupling lever from also being inserted into thestationary the via its open end when the final bearing, which guides thefork such that it can rotate, is arrange on the outer circumference ofthe stationary tube.

It is preferable if the fixed bearing which guides the fork such that itcan rotate is not arranged on the outer circumference of the stationarytube, but on its end face.

FIG. 1 shows a gas-blast power breaker in the region of two mutuallyopposite switching contacts, 1, 2, and the contact rod 3 which is fitwith the second switching contact 2. While, to the left of the centeraxis 4, the gas-blast power breaker is illustrated in the connectedposition, with the exception of a few components in the lower region,the gas-blast power breaker is illustrated in the disconnection positionon the right of the center axis 4.

As shown in FIG. 1, the two mutually opposite switching contacts 1, 2are surrounded, when connected, by an insulating material nozzle 5,coaxially with respect to which a shielding electrode 6 is arranged.While the insulating material nozzle 5 is connected to the firstswitching contact 1 which can be driven, that is to say carries out themovement of the first switching contact 1, which can be driven, during aswitching process, the shielding electrode 6 is not connected to theinsulating material nozzle 5.

In order now to ensure that an isolating gap to which high dielectricloads can be applied is formed during disconnection when the secondswitching contact 2 carries out a movement in the opposite direction tothe first switching contact 1, which can be driven, during operation ofthe latter, the insulating material nozzle 5 is connected to two tierods 7, 8 which are diametrically opposite one another with respect tothe center axis 4 and extend parallel to the contact rod 3. These tierods 7, 8 are firmly connected to a holder 9 nozzle 5. This holder 9 isarranged such that it can move axially on a stationary tube by thecontact rod 3, which is fit with the second switching contact 2, beingarranged such that it can move axially. Furthermore, two connecting rods11, 12, are arranged on the holder 9, which can move axially such thatthey can pivot, each of which is connected in an articulated manner to alimb 13, 14, of a fork 15, which is guided in a fixed bearing 16 suchthat it can rotate, which fixed bearing 16 is arranged on the end face17 of the tube 10 which holds the contact rod 3 such that it can moveaxially. The fork 15, which is shown on both sides of the center axis 4,with the gas-blast power breaker in the disconnected position, has alever 18 on its side opposite the limbs 13, 14, which lever 18 isconnected, such that it can pivot, to a coupling lever 19, which isconnected to the contact rod 3 which is fit with the second switchingcontact 2.

When disconnection takes place, the tie rods 7, 8 are driven via theinsulating material nozzle 5 during operation of the first switchingcontact 1, which can be driven. Since the holder 9 moves axially on thestationary tube 10, at the same time that the tie rods 7, 8 are driven,the connecting rods 11, 12 which are arranged on the holder 9 such thatthey can pivot, are also driven. Assuming that each of the connectingrods 11, 12 is connected to a limb 13, 14 of the fork 15 which is guidedin the fixed bearing 16 such that it can rotate, the fork 15 pivots inthe fixed bearing 16. While the limbs 13, 14 of the fork 15 move in thedirection of the holder 9, which can move axially, during this process,the lever 18, which is essentially opposite the limbs 13, 14, in thiscase moves in the opposite direction. However, this means that thecoupling lever 19, which is connected to this lever 18 such that it canpivot, drives the contact rod 3, by axial movement within the stationarytube, and hence drives the second switching contact 2 so that the lattercarries out a movement in the opposite direction from that of the firstswitching contact 1, which can be driven, during disconnection, thusforming an isolating gap which can be dielectrically highly loaded oncethe disconnection process has been completed.

In order now to achieve optimum control of the electric field in theswitching gap 20 during a switching process in this gas-blast powerbreaker as well, a further respective connecting rod 21, 22 is mountedin an articulated manner on each limb 13, 14 of the fork 15 and isconnected, such that it can pivot, to a second holder 23, which isarranged on the first holder 9 such that it can move axially. Two pushrods 24, 25 are now arranged in a fixed manner on this second holder 23and are connected to the shielding electrode 6 which is arrangedcoaxially with respect to the insulating material nozzle 5.

When the gas-blast power breaker carries out a disconnection process,the limbs 13, 14 of the fork 15 thus move the connecting rods 21, 22 andthe push rods 24, 25 in the direction of the switching gap 20. Since thepush rods 24, 25 are connected to the shielding electrode 6, the latterthus carries out a movement whose direction corresponds to that of thefirst switching contact 1. Since the connecting rods 21, 22, which aremounted in an articulated manner on the limbs 13, 14 of the fork 15, aremounted on the limbs 13, 14 in their central region, not only is themagnitude of the speed of the shielding electrode 6 less than that ofthe first switching contact 1, but also the distance traveled by theshielding electrode 6. The choice of the mounting point of theconnecting rods 21, 22 on the limbs 13, 14 of the fork 15 between thefixed bearing 16 and the articulated mounting 26, 27 of the connectingrods 11, 12, thus provides the preconditions for the shielding electrode6 to provide optimum control of the electric field in the switching gap20 during the switching process.

While, according to FIG. 1, the fixed bearing 16 which guides the fork15 such that it can rotate is arranged on the end face 17 of thestationary tube 10, this fixed bearing 16 in FIG. 2 is provided on theouter circumference of the stationary tube 10, which guides the contactrod 3. This is achieved in that, despite the necessity for the fork 15,there is no need to enlarge the switching chamber in the axial directionfor the movement sequence of the second switching contact 2 and of theshielding electrode 6 (FIG. 1). In this case, the fixed bearing 16 whichguides the fork 15 is arranged at a distance from the stationary tube10, and is mounted on its end face 17. In this arrangement of the fixedbearing 16, the coupling lever 19, which is connected to the lever 18 ofthe fork 15 such as it can pivot and is connected to the contact rod 3,passes through the stationary tube 10, via an elongated hole 20 in it.Both the arrangement of the connecting rods, of which only theconnecting rods 11 and 21 are illustrated here, and the configuration ofthe fork 15, of which only the limb 13 is illustrated here, correspondto the arrangement of the connecting rods 11, 12, 21, 22 and theconfiguration of the fork 15 with the two limbs 13, 14 shown in FIG. 1.

However, as can be seen from this figure, the angle α between the lever18 and the limb 13 and hence the limb 14 (FIG. 1) of the fork 15, isgreater than 90°, so that the contact rod 3 travels over a sufficientlylarge distance during disconnection in order to form an isolating gapwhich can be highly loaded between the switching contacts 1, 2 (FIG. 1).

What is claimed is:
 1. A high-voltage power breaker, comprising: firstand second mutually opposite switching contacts when connected, aresurrounded by an insulating material nozzle coaxially with respect towhich a shielding electrode is arranged, the second switching contactperforming a movement in the opposite direction to the first switchingcontact, which can be driven, during operation of the first switchingcontact, and the shielding electrode controllable based on coupling by alinkage to the second switching contact, in the movement direction ofthe first switching contact at a speed whose magnitude is less than thespeed of the first switching contact, wherein the insulating materialnozzle is connected to two tie rods which are diametrically opposite oneanother with respect to the center axis of the switch, and extendparallel to the second switching contact and are firmly connected on theside facing away from the insulating material nozzle to a first holder,the first holder is arranged such that it can move axially and on whichtwo connecting rods are arranged such that they can pivot, each of whichis connected in an articulated manner to one limb of a fork, the fork isguided such that it can rotate in a fixed bearing and has a lever on itsside essentially opposite the limbs, to which lever a coupling lever isconnected such that it can pivot and is connected to the contact rodwhich is fit to the second switching contact and can move axially. 2.The high-voltage power breaker as claimed in claim 1, wherein the angleα between the limbs of the fork and the lever is greater than
 90. 3. Thehigh-voltage power breaker as claimed in claim 1, further comprising:another connecting rod mounted in an articulated manner on each limb ofthe fork, the connecting rods each connected such that they can pivot toa second holder, which is arranged on the first holder such that it canmove axially, and on which two push rods are arranged in a fixed mannerand are connected to the shielding electrode.
 4. The high-voltage powerbreaker as claimed in claim 3, wherein, in the central region of thelimbs of the fork, the connecting rods are connected to the fork in anarticulated manner such that, during disconnection, the distancetraveled by the shielding electrode is shorter than that traveled by thesecond switching contact.
 5. The high-voltage power breaker as claimedin claim 4, wherein, the fixed bearing which guides the fork such thatit can rotate, is arranged on the outer circumference of a stationarytube guiding the contact rod, and at a distance from tube, and thecoupling lever, which is connected to the lever of the fork such that itcan pivot and is connected to the contact rod, is introduced into thestationary tube via an elongated hole within said stationary tube. 6.The high voltage power breaker as claimed in claim 5, wherein, the fixedbearing which guides the fork such that it can rotate, is connected tothe stationary tube.
 7. The high-voltage power breaker as claimed inclaim 4, wherein, the fixed bearing which guides the fork such that itcan rotate is arranged on the end face of a stationary tube which guidesthe contact rod.